No, but as a one-time exception I'll leave that thread, since I don't like deleting so many posts over a borderline case like this which wasn't otherwise acted upon for over a month. If somebody does the exact same thing in the future, it should be deleted.

If somebody doesn't have to look up the URL to visit the site after reading your post, using Google or some other such resource, then you're posting the URL in a disallowed way. This includes things like posting "examplemixer dot com", using a URL shortener, using a simple "click here to continue" landing page, etc. If there are two mixers which can't be disambiguated except by posting their full domain name, or if their official name is a full domain name, then that's an annoying situation, but it would not excuse posting their full domains.

But there seems to be some confusion around promotion. It would be allowed to post even a positive review thread for ExampleMixer, just as long as you don't post the URL and you don't violate the other rules. Promotion is only disallowed in signatures, avatars, and profile-bios; not posts.